Author: Hussam Ahmed
Date: October 26, 2024
Authentication systems serve as the gatekeepers to user accounts and sensitive data. Ensuring their security is crucial to prevent unauthorized access, data breaches, and loss of user trust. Email normalization—the process of standardizing email addresses—plays a critical role in maintaining the integrity of these systems. Inconsistent handling of email normalization can inadvertently allow attackers to bypass security measures, leading to account duplication and unauthorized access.
This article examines a specific vulnerability identified during a penetration test on an application leveraging Auth0 for authentication, highlighting the critical role of email normalization in maintaining authentication integrity.
The application under test utilizes Auth0 to handle user authentication, offering two primary methods for account creation:
Our focus is on the Email and Password registration method, as it interacts directly with Auth0's email handling and database configurations.
During an initial penetration test, a previously identified vulnerability was tested. By following the known exploit steps, an Account Takeover (ATO) was successfully achieved. Upon discovering this vulnerability, it was promptly reported to the client, and immediate actions were taken to fix the issue.
YOU can read the Write-up here: https://medium.com/@iknowhatodo/exploiting-auth0-misconfigurations-a-case-study-on-account-linking-vulnerabilities-76fb6b9703f8